Dermatology Flashcards
Primary skin lesion
Has not been altered by outside manipulation, treatment, natural course of disease. Ex- vesicles
Secondary skin lesion
Lesions altered by outside manipulation, treatment, natural course of disease.
Ex- crust from ruptured vesicles, excoriation, lichenification, scales, erosion, ulcer, fissure
Macule
Flat, non-palpable.
Papule
Solid elevation,
Pustule
Vesicle-like lesion with purulent content,
Umbilicated
Papule with indented center
Patch
Flat, non-palpable area of skin discoloration larger than a Macule. >1cm
Ex- vitiligo
Plaque
Raised lesion, same or different color from surrounding skin, can result from a coalescence of papules >1cm
Ex- psoriasis vulgaris
Bulla
Fluid-filled >1cm
Ex- 2nd degree burn (blister)
Cyst
Raised, encapsulated, fluid filled lesion
Ex- intradermal cyst
Wheal
Circumscribed area of skin edema
Ex- hives, ppd
Purpura, petechiae
Flat red-purple discoloration that does not blanch with pressure.
>1cm= purpura
Lichenification
Skin thickening usually found over pruritic or friction areas
Confluent lesions
Multiple lesions blending together
Ex- psoriasis, tinea
Annular lesions
In a ring, often seen in the characteristic “Bulls eye” lesion seen in Lyme disease
Actinic keratoses
Brown, occasionally skin colored, scaly. Can be felt by running finger over area. Feels rough like Sand paper.
Most common precancerous skin lesion, can remain unchanged, spontaneously resolve, or progress to invasive squamous cell carcinoma.
Basal cell
Most common, sun-exposed areas, arise on their own (de novo), pearly, waxy appearance, with relatively distinct borders.
Papule, nodule with or without central erosion
Mets risk low, significant tissue destruction risk without treatment.
Squamous cell
Less common, can arise from nothing, KERATINIZING CELLS or AK’s.
Red, conical hard lesions with or without ulceration, less distinct borders.
Mets risk greater than BCC, (3-7%), significant tissue destruction without treatment. Greatest risk on lip, oral cavity, genitalia
ABCDE of malignant melanoma
Asymmetric
Borders irregular
Color not uniform (brown, black, red, blue)
Diameter (usually >6mm)
Evolving new lesion or change in a lesion, particularly a nevus or other pigmented lesion.
Elevated
Impetigo organisms
Staphylococcus aureus
Streptococcus pyrogenes
Erysipelas definition & organisms
Hot, red, infection of the upper dermis, superficial lymphatics.
Streptococcus pyrogenes (requires IV Pcn)
Cellulitis organisms
Streptococcus pyrogenes, less commonly staphylococcus aureus MSSA/MRSA
Cutaneous abscess/furuncle, carbuncle organism
Staphylococcus aureus MSSA/ MRSA
Treatment for cellulitis/erysipelas/impetigo
Moderate (systemically Ill, tracking/streaking)- IV penicillin, ceftriaxone IV, cefazolin IV, or clindamycin IV
Mild- pen VK, cephalexin, dicloxacillin, or clindamycin po
Treatment of abscess/carbuncle/furuncle
Moderate (tracking/streaking, lymphadenopathy)- I&D, C&S, TMP/SMX or doxycycline
Mild- I&D, no abt
1st degree burn
Superficial burns- impacts epidermis only; no blisters present.
2nd degree burn
Superficial partial thickness- upper layers of papillary dermis
Deep partial thickness- deeper layers of dermis, including reticular dermis
Blisters present
3rd degree burns
Full thickness- epithelium, dermis & underlying fat layer.
Body ringworm aka
Tinea corpois
Jock itch aka
Tinea cruris
Athletes foot aka
Tinea pedis
Fungal infection of scalp aka
Tinea capitis
Pityriasis rosea description & key findings
Oval, salmon-colored scaling plaques.
Acute, exanthematous eruption.
Classically starts with a HERALD PATCH
secondary phase erupts in a CHRISTMAS TREE PATTERN
Secondary syphilis rash
Looks similar to pityriasis rosea, but also presents on palms of hands & soles of feet.
Order RPR to check for evidence of syphilis
Psoriasis definition
Common, chronic, inflammatory mulit-system disease that mostly involves skin & joints
Presents as classic pink to bright red WELL-DEMARCATED PLAQUES WITH SILVERY SCALE
Usually on extensor knees & elbows
Guttate psoriasis description
Presents as small “drop-like” scaly papules and plaques mostly on the trunk and extremities
Often FOLLOWS GROUP A HEMOLYTIC STREPTOCOCCAL INFECTION
Inverse/flexural psoriasis
Erythematous patches located in the skin folds (axilla, groin).
May lack scale due to moistness of area. Often symmetric
Pustular psoriasis
Psoriatic lesions with pustules
Often TRIGGERED BY STEROID WITHDRAWAL
when generalized, it can be life-threatening
Palmoplantar psoriasis
May occur as plaque or pustular type.
Indistinguishable from rash of reactive arthritis
Psoriatic erythroderma
Involves almost the entire skin surface. BRIGHT RED, hospitalization is sometimes required
Auspitz sign
Bleeding after removal of scale (psoriasis scale)
Koebner phenomenon
Psoriasis lesions induced by trauma
Psoriasis treatment
Topical high potency steroids sometimes in combination with topical vitamin D analogs (topicals when
Lice (head, body, pubic)
Head- pediculus humanus var. capitis
Body- pediculus humanus var. corporis
Pubic- phthirus pubis
Pediculosis treatments
Permethrin 1%
Malathion 0.5% when resistance is suspected.
Scabies (sarcoptes scabiei) features
Hallmark is ITCHING AT NIGHT
papules may commonly involve the axillae, breasts, umbilicus, penis, scrotum, finger web and wrists.
Bed bug (cimex lectularius) treatment
Potent topical steroids and antihistamines
